Alex Salmond has appointed his most senior MP to lead the Nationalists’ ‘No to
Scotland in Britain’ campaign in the run-up to his independence referendum.

Angus Robertson, the SNP’s group leader at Westminster, is to spearhead the propaganda drive for separation after overseeing the party’s wildly successful Holyrood re-election campaign.

With opinion polls showing only about a third of Scots support his arguments, Mr Robertson promised to spell out the case for independence “in more depth and detail than ever before”.

Opposition parties said his appointment so early in the SNP’s second term is another sign that “all systems are go” for the First Minister’s plan to break up Britain.

But Mr Robertson refused demands from the Tories to specify the referendum date or question, despite the SNP’s unprecedented majority at Holyrood meaning they can stage it at a time of their choosing.

The SNP defence spokesman will also be expected in his new role to provide the detailed costs of independence, including a separate welfare system, diplomatic service and insurance against another banking crisis.

He will require a new plan for a separate Scotland’s armed forces after Sir Mike Jackson, one of Britain’s most respected generals, recently dismissed the SNP’s proposals to continue sharing troops and facilities with England.

SNP ministers have spent the month since the election campaign demanding more financial powers and picking a fight over the UK Supreme Court, but have failed to tackle a series of domestic issues, such as a university funding crisis.

Mr Robertson argued that this was because the election result, which saw the SNP win 69 out of 129 seats, showed clear public support “to move the country’s constitution forward”.

“The debate is no longer between change or no change – it’s about the kind of change Scotland wants, and above all, the right of the people to choose their future in a free and fair referendum,” the Moray MP said.

“In the days, weeks and months ahead we will set out the case for independence in more depth and detail than ever before. We will campaign positively and take our case to the people.”

He claimed the “vast majority” of Scots want to extend Holyrood’s powers, suggesting that he favours adding a third option to the referendum ballot paper of giving Scottish ministers full control over taxation.

Mr Salmond has only said the vote will be staged in the second half of his five-year term, but opposition parties argued that Mr Robertson’s appointment means there is no excuse for the SNP not to provide more specific information.

Murdo Fraser, Scottish Conservative deputy leader, said: “Now that he has been installed as the man in charge of the ‘No to Scotland in Britain’ campaign, perhaps Angus Robertson would like to come clean on when the referendum will be and what the question will be? Is he scared to say or doesn’t he know?”

Willie Rennie, Scottish Liberal Democrat leader, said: “At last we might get some of the details on the all potential costs of separation that we need for an informed debate.

“With Angus’s appointment, and his reputation for clarity, we should be able to see the costs of having a separate welfare system, foreign policy and diplomatic services, the costs of insurance you will require to protect us against any further banking crisis, as well as defence.”

A Scottish Labour spokesman added: “The SNP exist to break Scotland off from the rest of the UK, so it is hardly surprising that just days into their second term of government they are already firing up the campaign machine to break up Britain.

“During the SNP’s election campaign separation was the elephant in the room, but now it would seem all systems are go.”